WASHINGTON — Washington and Doha Wednesday signed an agreement for the purchase of F-15 fighter jets with an initial cost of USD12 billion.

The sale "will give Qatar a state-of-the-art capability and increase security cooperation and interoperability between the United States and Qatar", the Pentagon said in a statement.

The aircraft purchase was completed by US Defence Secretary James Mattis and his Qatari counterpart Khalid Attiyah during his visit to Washington DC.

Defence Secretary Mattis and Qatari Minister of State for Defence Affairs Attiyah also tackled the current state of operations against the Daesh terror group and the importance of de-escalating tensions so all partners in the gulf region can focus on next steps in meeting common goals, the Pentagon added.